A patterned polystyrene-based microelectrode array for in vitro neuronal recordings

Substrate-integrated microelectrode arrays (MEAs) are non-invasive platforms for recording supra-threshold signals, i.e. action potentials or spikes, from a variety of cultured electrically active cells, and are useful for pharmacological and toxicological studies. However, the MEA substrate, which is often fabricated using semiconductor processing technology, presents some challenges to the user. Specifically, the electrode encapsulation, which may consist of a variety of inorganic and organic materials, requires a specific substrate preparation protocol to optimize cell adhesion to the surface. Often, these protocols differ from and are more complex than traditional protocols for in vitro cell culture in polystyrene petri dishes. Here, we describe the fabrication of an MEA with indium tin oxide microelectrodes and a patterned polystyrene electrode encapsulation. We demonstrate the electrochemical stability of the electrodes and encapsulation, and show viable cell culture and in vitro recordings.